Heath Ledger's family sets the record straight on rumours The Joker left him depressed

Nine years on from his death, Heath Ledger's family has finally confronted the rumours that playing The Joker had left the actor in a troubled mental state.

Ledger, 28, died in January 2008 of an accidental intoxication from prescription drugs, just a few months after wrapping up filming for his role as the villain in Christopher Nolan's The Dark Knight.

After years of speculation that 'method' acting had contributed to his insomnia and subsequently untimely death, his sister Kate rubbished the claims at the New York premiere of new documentary I Am Heath Ledger.

The Dark Knight featuring Heath Ledger. Photo / Getty

"I was really shocked, because that was him having fun," she told the UK Daily Telegraph.

"Every report was coming out that he was depressed and that [the role] was taking this toll on him, and we're going, honestly, it was the absolute opposite. It couldn't be more wrong."

She added that he was far from depressed over the role.

"He had an amazing sense of humour, and I guess maybe only his family and friends knew that, but he was having fun. He wasn't depressed about the Joker."

Just last year, Ledger's father Kim told news.com.au there was no one to blame for the tragedy but his son.

"The last conversation Kate had with him was this discussion about his medications and she warned him, "You can't mix drugs that you don't know anything about'," he said.

The family of late actor Heath Ledger. Photo / Getty

"He said 'Katie, Katie, I'll be fine'. Well, that's a cavalier boy's answer. It just put his whole system to sleep I guess."

I Am Heath Ledger will screen in Australian cinemas for one week only from Thursday May 11. The list of participating cinemas can be found at iamheathledger.com.au.